There's a very brief flash of genuine surprise apparent on Hans' face. An abundantly clear moment of 'oh fuck'. What Rat doesn't see is the wheels turning quickly. Nothing in Rat's manner indicated that there were others hiding, though it's a viable possibility his gut doesn't allow him to move his focus from the fight. For a moment, it seems like he'll peer over his shoulder, only for his expression to change as he braces, allowing himself to move backward only inches.

"Not a chance." He chides. When the kick comes toward him, he'll block it with his sword, allowing Rat's momentum to doom him, even if it takes a toll on his wrists.